., with historian richard norton smith. >> sreenivasan: walking into the theater center is like taking a step back in time to the cobblestone streets of washington on april 16, 1855, the day after president abraham lincoln's death. newspaper headlines cover the walls of the new exhibit which ...in a building across the street from ford's theater where the president was assassinated. >> you walk to the third floor and you come to this mothy attic. the chronological treatment. >> reporter: presidential historian richard norton smith, who helped design the center, says its mission is to examine how lincoln has influenced americans great and small since his death. in part, that influence is symbolized by the 34-foot-high book tower that connects the center's three floors. it's made of aluminum and represents some of the roughly 15,000 works written about lincoln. >> the story didn't end on april 15. in some ways, the story begins. the story of what we want lincoln to be. which lincoln are we talking about? the evolution of the posthumous lincoln. it's like a mirror held up to the evolution